Telephone-receiver shell.



J. F. BARBOUR.

TELEPHONE RECEIVER SHELL.

APPLICATION FILED SEPT. 27, 1909.

Patented June 11, 1912.

W w W r m M M 6 w W? 2 8,59 m FE W I JOHN F. BABBOUR,

or ELYRIA, onro, as srenonwrounn DEAN ELECTRIC compan Q1 ELYRIA, OHIO, A CORPORATION OF OHIO.

TELEPHONE-RECEIVER SHELL.

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Specification of Letters Patent.

Patented June 11, 1912.

Application filed September 27, 1909. Serial No. 519,747.

" My invention relates to telephone receivers, and has for its object a construction of a receiver shell of metal which shall accom-- plish all of thep urposes heretofore secured in connection with shells for such instruments and having the additional advantage of lightness, durability and cheapness.

Receiver shells have commonly been made hitherto of insulating material of one form or another which, generally speaking, is very brittle in nature, and, therefore, easilybroken. To avoid this difliculty, the shells have usually been constructed of considerable thickness with the result .that they are both clumsy and heavy. By my invention I construct these shells of thin sheet metal and form a slot therein which is adapted to coiiperate with a lug on the cap. The receiver cap may be constructed in one piece; that is, it may consist in a main portion formed of thin sheet metal having a lug formed thereon which cotiperates with theslot. If preferred, a cap of insulating materialmay be used in connection with the metal shell instead of the metallic cap which is referred to.

In constructing my improved receiver shell, I make use preferably of forming dies 'to form suitable sheet metal into the desired conformation. In order to be readily manipulated so as'to assume the form required, the sheet metal used must be preferably relatively thin. This thinrhaterial, however, is

not adapted to be threaded, since the threads would be so fine necessarily as to be of no use. Furthermore, the threaded portion would not possess suflicient rigidity to readily engage the cotiperating threaded member. By my invention I eliminate this difficulty by forming an angular slot in the thin metal forming either the body portion or the cap, and create upon the other member a lug which cotiperates with this slot. This joint s commonly known as a bayonet jolnt,

though I do not limit myself to an angular slot as shown in the drawing.

A further advantage secured by this construction is that the receiver shell is comparatively light. In the event of forming the shell of material thin enough to be properly threaded, the shell would be so heavy as to practically prohibit its use.

A further advantage secured by my im- 'bility of corrosion of the threads engaging proper,

each other may be eliminated. If a steel shell ha: d formed directly thereon the threads for engaging the cap, serious difficulty would result from the corrosion of the steel threads; and in many cases, would make it practically impossible to remove the cap from the re-" ceiver after the same had been in use for sometime. This result would occur particularly in the case in which both the receiver and the cap were made of steel, each having the threads carried thereby, formed directly in the steel itself.

In connection with the use of sheet steel for forming the main portion of the shell I mploy a protecting varnish or coating, for example, enamel or japan, to thoroughly protect the steel from the contact of moisture. be used satisfactorily to protect the steel screw threads above referred to, since evidently the screw threads in order to properly perform their function, must be clean and free from any foreign matter.

My invention will be best understood by reference to the followingX description when taken in connection wit the accompanying illustration showing one specific em bodiment thereof, while its scope will be more particularly pointed out in. the appended claims.

Figure 1 is a side elevation of a fragment of the body portion and of the cap of the casing. Fig. 2 is an end elevation of the body portion. Fig. 3 is a longitudinal cross section showlng the cap connected to the body.

This means could not Referring now to the drawing, I have illustrated a receiver casing or shell having a main body portion 1 and a cap portion 2. In the body portion I show a slot 3 having a portion 4 at an angle to the main part thereof. On the cap 2 I show a lug 5 adapted to engage the slot and connect-the body portion to the shoulder. At 6 I show an insulating disk which fits between the body portion and the cap. I have shown on the body portion of the shell a shoulder 7 in which the slot is formed," and on the cap portion, a shoulder-8 on which the lug is formed. These shoulders cooperate with each other when the parts are joined together. In connecting the members, the lug is pushed into'the angular part of the slot 4, and the parts pushed together until thelug engages the rear of the slot 3. One of the members is then r'ot-ated until the lug 5 closes the part 4. The two parts are then firmly secured. togethen This joint is commonly known as a bayonet joint. I may provide more than one of these joints for each cap and shell, as I shall elect. As a matter of fact, in constructing these shells,

I propose to use three of these joints, al-

though I may use more or less, as is expedient. I may also reverse the position of the lug and slot, placing the slot in the cap and the lug on the body portion, if I desire, the same beingcontemplated in my invention.

While I have shown my invention in this particular form, it will be obvious to those skilled in the art that numerous and ex- -tensive departures from'theform and details herein shown may be made without departing from the spirit of this invention, the same being shown solely for the purpose of clearly illustrating one specific embodiment thereof. I

I claim:

1; In a telephone receiver shell adapted to house telephone receiver mechanism, a main portion made of sheet metal of substantially tubular shape and expanded at one end into. a bell shape, said expanded end being open, the exterior edge of said open end being extended to form an annular portion substantially parallel to the long axis of said main portion, a plurality of bayonet slots pressed into the metal of said annular portion, the long arms of said slots being parallel to-the edge of the open end of the main portion, a sheet metal cap for said shell, said cap having its top depressed to form a crater like receptacle for der, hollow lugs formed on the inside ofsaid bent over edges of'the material of said cap and adapted to enter said bayonet slots when the cap is mounted on the shell to unite said cap and shell, said lugs friction- "all-y engaging the top and sides of said slots to prevent relative movement between the cap and main port-ion when the two are united.

2. In a telephone receiver shell, adapted to house telephone receiver mechanism, a mam portlonrmade' of sheet metal substantially tubular in shape and expanded at one end into a bell shape, said expanded end being open, the exterior of said open end being extended to form an annular portion having its walls substantially parallel to the long axis of said main portion, a plurality of bayonet slots pressed int-o the -metal of said annular. portion, the long' arms of said slots being substantially parallel to the edge of the open end of the main portion, a sheet metal cap for said shell, said cap having its top depressed to form a crater like receptaclefor the ear and perforated at the center to permit the passage of sound waves to the ear, the edge of the cap being bent over to form an annular portion substantially parallel to the long axis.

of the main portion when the cap is mounted on the main portion and lugs on the inside of said bent over edges of said cap adapted to enter said bayonet slots when the cap is mounted on the shell to unite said cap and shell, said lugs frictionally engaging the top and sides of said slots to prevent relative movement between the cap and main portion when the two are united.

In testimony whereof I atfix my signature in presence of two witnesses.

JOHN F. BARBOUR.

Witnesses:- I

' J. M. LENZ,

F. L. CLARK. 

